Historically, physics education research has guided development of instructional strategies that significantly boost conceptual understanding. Recently, efforts have expanded to more implicit instructional goals, such as promoting expert-like views about what must be done to learn new physics ideas. Progress in promoting the "hidden" curriculum has been slow: most pre/post measurements have in fact yielded negative gains. At Western Washington University, we are exploring ways of promoting student reflection, a backward-looking form of metacognition.* Experts somehow develop the conscious habit of reviewing what they have learned and checking for gaps in their understanding, but what can be done to hurry the process along? In the context of a lab-based reflection activity, we have collected written and video data, with twin goals of guiding modification to the instruction and contributing to the knowledge base on student metacognition. This talk will describe the instructional approach and illustrate specific modes of student reflection. *Work supported by NSF DUE-1245993.